From FR-A-2.442.987 a device of the aforenoted type is already known which comprises a foot which is introduced into an opening of standard shape in a carrier element, the foot being equipped with two pairs of mutually opposite lugs, one of which comprises a crosspiece in the form of a wedge which points towards a slot located between the lugs of the other pair, the blocking of the fixing device on the carrier element being effected by manipulating a rod which moves the crosspiece so that the wedge penetrates into the slot and the pair of lugs carried by the crosspiece flex while the other pair of lugs are caused to bend outwards by the wedge.
In general the crosspiece is controlled by means of a screw with a self-cutting threaded shank with which it co-operates.
This type of device is highly regarded because it provides a high quality fixation because each of the four lugs deforms outwards during the fixing step, because it is suitable for a carrier element the thickness of which may vary over a relatively large range, and lastly because this type of device can usually be removed without any part remaining in the carrier element.